Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D65/00—Wrappers or flexible covers; Packaging materials of special type or form
  • B65D65/38—Packaging materials of special type or form
  • B65D65/40—Applications of laminates for particular packaging purposes
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
  • C09J11/08—Macromolecular additives
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J167/00—Adhesives based on polyesters obtained by reactions forming a carboxylic ester link in the main chain; Adhesives based on derivatives of such polymers
  • C09J167/08—Polyesters modified with higher fatty oils or their acids, or with natural resins or resin acids
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J191/00—Adhesives based on oils, fats or waxes; Adhesives based on derivatives thereof
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J7/00—Adhesives in the form of films or foils
  • C09J7/30—Adhesives in the form of films or foils characterised by the adhesive composition
  • C09J7/35—Heat-activated
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
  • Y02W90/00—Enabling technologies or technologies with a potential or indirect contribution to greenhouse gas [GHG] emissions mitigation
  • Y02W90/10—Bio-packaging, e.g. packing containers made from renewable resources or bio-plastics

Definitions

• the present invention relates to a two-component curing adhesive composition, a laminate obtained by laminating various substrates with the adhesive, and a packaging material.
• Laminated films (sometimes called laminate films) used for various packaging materials, labels, etc., are given design, functionality, storage properties, convenience, and transportability by laminating a wide variety of plastic films, metal foils, etc., and in particular, packaging materials made by forming such laminated films into bags are used as packaging materials for food, medicines, detergents, etc.
• a reactive adhesive also called a two-component adhesive
• combines a polyisocyanate composition and a polyol composition is known.
• Reactive adhesives that combine polyisocyanate compositions and polyol compositions have many advantages, including not only high adhesive strength but also a moderate curing speed and abundant raw material sources. However, they have problems such as difficulty in handling due to the high reactivity of isocyanates (skin sensitization, inhalation toxicity) and the generation of primary aromatic amines, which are carcinogenic substances, during the curing reaction, and there is a demand in the market for safer reactive adhesives.
• biomass a biological resource
• plants grow by absorbing carbon dioxide from the atmosphere through photosynthesis using sunlight as energy. Therefore, products made from plant-derived raw materials (biomass plastics, synthetic fibers, etc.) are expected to be developed because the amount of carbon dioxide absorbed by photosynthesis during the plant's growth process is offset by the amount of carbon dioxide emitted from the incineration of the plant, and it is thought that such products will not affect the increase or decrease of carbon dioxide in the atmosphere (carbon neutral).
• the biodegradable resins that have been reported are often highly viscous, and the use of organic solvents is essential for their use, so the impact of the organic solvents discharged after use on the environment cannot be ignored. Thus, it is currently not possible to achieve both biodegradability and adhesiveness that meet the standards required by the market. For these reasons, adhesives that combine recyclability and biodegradability are not yet on the market.
• the problem that the present invention aims to solve is to provide a reactive adhesive composition that is highly safe, has adhesive strength comparable to that of conventional reactive adhesives that combine polyisocyanate compositions and polyol compositions, and provides excellent recyclability and biodegradability for the laminated film.
• the present invention provides an adhesive composition that comprises an oil (A) containing an acid anhydride group and a curing agent (H), the curing agent (H) containing an acid-modified polyol (B) and an amine compound (C).
• the present invention also provides a laminate comprising a first substrate, an adhesive layer, and a second substrate laminated in this order, the adhesive layer being the adhesive composition.
• the present invention also provides a packaging material formed by molding the laminate into a bag shape.
• the adhesive composition of the present invention is highly safe, has adhesive strength comparable to that of conventional reactive adhesives that combine polyisocyanate compositions and polyol compositions, and forms a laminate film that is not only excellent in recyclability but also in biodegradability. Because it is highly safe and has excellent recyclability and biodegradability, it can be particularly well suited for use as food packaging bags.
• the fat or oil (A) used in the present invention contains an acid anhydride group.
• Fats and oils are substances having a structure of esters of fatty acids and glycerin, i.e., triglycerides, and are widely present in the natural biological world.
• the fats and oils (A) containing an acid anhydride group used in the present invention are preferably fats and oils (A) containing an acid anhydride group, which are obtained by introducing (adding) an acid anhydride group into fats and oils containing double bonds derived from unsaturated fatty acids in their chemical structure.
• fats and oils containing double bonds derived from unsaturated fatty acids in their chemical structure include drying oils (iodine value >130) and/or semi-drying oils (iodine value 100 to 130), and examples of vegetable oils include tung oil, linseed oil, perilla oil, safflower oil, dehydrated castor oil, safflower oil, soybean oil, rapeseed oil, sunflower oil, sesame oil, rice oil, cottonseed oil, corn oil, tall oil, poppy seed oil, walnut oil, pine seed oil, etc.
• animal oils include fish oils (sardine oil, saury oil, herring oil, etc.).
• regenerated vegetable oils that have been used for edible purposes, such as tempura oil, and then recovered/regenerated can also be used.
• oils and fats tung oil, soybean oil, rapeseed oil, and linseed oil are preferably used because of their easy availability.
• the acid anhydride-containing compound used to introduce an acid anhydride group into the oil or fat may be a compound having a double bond in the molecule, such as maleic anhydride, citraconic anhydride, or tetrahydrophthalic anhydride. Of these, maleic anhydride is preferred due to its ease of introduction and the reactivity of the acid anhydride group.
• maleic anhydride as an example of an acid anhydride group-containing compound.
• the amount of maleic anhydride introduced is preferably 19 to 34 g (0.19 to 0.35 mol), more preferably 22 to 29 g (0.22 to 0.30 mol) per 100 g of oil or fat. If the amount of maleic anhydride introduced is too large, the viscosity may increase significantly, making handling difficult.
• a known method can be used to add maleic anhydride to fats and oils.
• a drying oil is used as the fat and oil
• a method of carrying out a Diels-Alder reaction with maleic anhydride at 50 to 150°C, more preferably 60 to 120°C can be used.
• a semi-drying oil is used as the fat and oil
• maleic anhydride can be introduced into the fat and oil by a method of carrying out an Alder-Ene reaction at 150 to 250°C, more preferably 180 to 220°C.
• a method can also be used in which maleic anhydride is reacted with semi-drying oil until a certain reaction rate is reached, and then drying oil is added to react with the remaining maleic anhydride.
• a small amount of organic peroxide or a known polymerization inhibitor may be added.
• examples of such polymerization inhibitors include benzoquinone, hydroquinone, hydroquinone monomethyl, tert-butylhydroquinone, dibutylhydroxytoluene, and 4-tertiarybutylcatechol.
• a method of blowing air into the mixture can also be used.
• Acid-modified polyol (B) In the present invention, by using the acid-modified polyol (B) as a curing agent, it is possible to impart alkali solubility while maintaining adhesiveness, and also to exhibit excellent biodegradability.
• the acid-modified polyol (B) used in the present invention is a polyol having an acidic group in the polyol molecule.
• the acidic group include a carboxyl group and a phosphoric acid group, and among these, a carboxyl group is preferred from the viewpoint of ease of production.
• the method for producing the acid-modified polyol (B) is not particularly limited, but a method of adding an acid anhydride-containing compound to the hydroxyl group of various polyols to introduce a carboxyl group is preferably used.
• the acid anhydride-containing compound to be added to various polyols examples include trimellitic anhydride, phthalic anhydride, hexahydrophthalic anhydride, succinic anhydride, maleic anhydride, pyromellitic anhydride, etc., and among them, trimellitic anhydride is preferably used.
• the polyester polyol can be produced by adjusting the composition so that it has both hydroxyl groups and carboxyl groups.
• Polyester polyols include, for example, dibasic acids such as terephthalic acid, isophthalic acid, phthalic anhydride, adipic acid, azelaic acid, sebacic acid, and dimer acid (a liquid fatty acid containing monobasic and tribasic acids as well as C36 dibasic acids produced by dimerization of C18 unsaturated fatty acids derived from vegetable oils and fats as the main component) or their dialkyl esters, or mixtures thereof, and, for example, ethylene glycol, propylene glycol, diethylene glycol, butylene glycol, neopentyl glycol, 2-methyl-1,3-propanediol, 1,6-hexanediol, 3-methyl-1,3-propanediol, 1,6-hexanediol, 1,6-methyl-1,3-propane ...
• dibasic acids such as terephthalic acid, isophthalic acid, phthalic anhydride,
• polyester polyols examples include polyester polyols obtained by reacting glycols such as 1,5-pentanediol, 3,3'-dimethylolheptane, polyoxyethylene glycol, polyoxypropylene glycol, and polytetramethylene ether glycol with trihydric or tetrahydric alcohols such as glycerin (glycerol), trimethylolethane, trimethylolpropane, and pentaerythritol, or mixtures thereof, and polyester polyols obtained by ring-opening polymerization of lactones such as polycaprolactone, polyvalerolactone, and poly( ⁇ -methyl- ⁇ -valerolactone).
• glycols such as 1,5-pentanediol, 3,3'-dimethylolheptane
• polyoxyethylene glycol polyoxypropylene glycol
• polytetramethylene ether glycol examples include polytetramethylene ether glycol with trihydric or t
• a glycol such as ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, or 1,6-hexanediol, or a trihydric or tetrahydric alcohol such as glycerin, trimethylolethane, trimethylolpropane, or pentaerythritol to which the above-mentioned acid anhydride group-containing compound has been added.
• the method of adding an acid anhydride group-containing compound to a polyester polyol is preferred because it can provide excellent delamination properties and biodegradability.
• the acid value of the acid-modified polyol (B) is preferably in the range of 5 to 40 mg KOH/g, and more preferably in the range of 10 to 30 mg KOH/g.
• the acid value is a value measured according to JIS K0070.
• the hydroxyl value of the acid-modified polyol (B) is preferably 50 to 330 (mg-KOH/g), and more preferably in the range of 100 to 250. If the hydroxyl value is less than 50 (mg-KOH/g), the viscosity of the acid-modified polyol (B) may become high and handling may become difficult, whereas if the hydroxyl value exceeds 330 (mg-KOH/g), sufficient adhesive strength may not be obtained.
• the hydroxyl value is a value measured in accordance with JIS K0070.
• the molecular weight of the acid-modified polyol (B) is in the range of 1500 to 8000 as the weight average molecular weight, and more preferably in the range of 2500 to 5000.
• the molecular weight is a value measured by gel permeation chromatography (GPC) under the following conditions.
• Measurement device High-speed GPC device ("HLC-8220GPC” manufactured by Tosoh Corporation) Column: The following columns manufactured by Tosoh Corporation were used in series connection. "TSKgel G5000” (7.8mm I.D. x 30cm) x 1 "TSKgel G4000” (7.8mm I.D. x 30cm) x 1 "TSKgel G3000” (7.8mm I.D. x 30cm) x 1 "TSKgel G2000" (7.8mm I.D.
• the curing agent preferably contains at least one amine compound (C) in addition to the acid-modified polyol (B).
• the amine compound (C) not only contributes to the formation of a cured adhesive as a curing agent, but also improves the curing speed by allowing the nitrogen contained in the structure to act as a catalyst to promote the reaction between the acid anhydride group and the hydroxyl group.
• the amine compound (C) may be one type of amine compound or a combination of multiple types of amine compounds.
• the amine compound (C) is preferably a compound containing two or more primary and/or secondary amino groups in one molecule, or a compound containing one or more tertiary amino groups in one molecule, and examples thereof include tertiary amine-containing polyol (B2) having multiple hydroxyl groups, amide polyol, polyamine, etc.
• the tertiary amine-containing polyol (B2) is preferably used because it is easy to adjust the balance between the reactivity with the oil (A) containing an acid anhydride group and the physical properties of the film formed.
• an amino alcohol having both a primary or secondary amino group and a hydroxyl group in one molecule can also be used. Examples of such amino alcohols include monomethanolamine, N-methylmethanolamine, N-ethylmethanolamine, dimethanolamine, monoethanolamine, N-methylethanolamine, N-ethylethanolamine, diethanolamine, etc.
• the tertiary amine-containing polyol (B2) is preferably a tertiary amine compound having a plurality of hydroxyl groups, particularly preferably having 2 to 6 hydroxyl groups.
• the tertiary amine-containing polyol may have one or more tertiary amino groups, but preferably has 1 to 2 tertiary amino groups.
• Specific examples include polypropylene glycol ethylene diamine ether, tri(1,2-polypropylene glycol)amine, N-ethyldiethanolamine, N-methyl-N-hydroxyethyl-N-hydroxyethoxyethylamine, pentakishydroxypropyldiethylenetriamine, and tetrakishydroxypropylethylenediamine.
• a commercially available product may be used as the tertiary amine-containing polyol (B2).
• Examples of commercially available products include TE-360 (a tertiary amine-containing trifunctional polyol manufactured by Guodu Chemical Co., Ltd. (China)), TD-401 (a tertiary amine-containing tetrafunctional polyol manufactured by Guodu Chemical Co., Ltd. (China)), EDP-300, EDP-450 (all tertiary amine-containing tetrafunctional polyols manufactured by Adeka Corporation), etc.
• amide polyols examples include polyesteramide polyols, and polyesteramide polyols obtained by using an aliphatic diamine having an amino group, such as ethylenediamine, propylenediamine, or hexamethylenediamine, as a raw material in the esterification reaction of the polyester polyol.
• the polyamine is not particularly limited, and any known polyamine having a primary and/or secondary amino group can be used.
• the polyamine may also contain a tertiary amine.
• aliphatic diamines include alkylene (having 2 to 6 carbon atoms) diamines such as ethylenediamine, propylenediamine, trimethylenediamine, tetramethylenediamine, and hexamethylenediamine, and polyalkylene (having 2 to 6 carbon atoms) diamines such as diethylenetriamine, iminobispropylamine, bis(hexamethylene)triamine, triethylenetetramine, tetraethylenepentamine, and pentaethylenehexamine,
• Alkyl (1-4 carbon atoms) or hydroxyalkyl (2-4 carbon atoms) substituted aliphatic diamines such as dialkyl (1-3 carbon atoms) aminopropylamine, trimethylhexamethylenediamine, aminoethylethanolamine, 2,5-dimethyl-2,5-hexamethylenediamine, and methyliminobispropylamine,
• Aliphatic diamines containing alicyclic or heterocyclic rings include alicyclic diamines (4-15 carbon atoms) such as 1,3-diaminocyclohexane, isophoronediamine, menthenediamine, and 4,4'-methylenedicyclohexanediamine (hydrogenated methylenedianiline), and heterocyclic diamines (4-15 carbon atoms) such as piperazine, N-aminoethylpiperazine, 1,4-diaminoethylpiperazine, and 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiro[5,5]undecane,
• Examples include xylylenediamine and tetrachloro-p-xylylenediamine, which are aromatic ring-containing aliphatic amines (8 to 15 carbon atoms).
• Aromatic diamines (6 to 20 carbon atoms) include unsubstituted aromatic diamines such as 1,2-, 1,3-, or 1,4-phenylenediamine, 2,4'- and 4,4'-diphenylmethanediamine, crude diphenylmethanediamine (polyphenylpolymethylenepolyamine), diaminodiphenylsulfone, benzidine, thiodianiline, 2,6-diaminopyridine, m-aminobenzylamine, triphenylmethane-4,4',4"-triamine, and naphthylenediamine,
• aromatic diamines such as 1,2-, 1,3-, or 1,4-phenylenediamine, 2,4'- and 4,4'-diphenylmethanediamine, crude diphenylmethanediamine (polyphenylpolymethylenepolyamine), diaminodiphenylsulfone, benzidine, thiodianiline, 2,6-di
• Aromatic diamines having a nucleus-substituted alkyl group such as 2,4- or 2,6-tolylenediamine, crude tolylenediamine, diethyltolylenediamine, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-bis(o-toluidine), dianisidine, diaminoditolylsulfone, 1,3-dimethyl-2,4-diaminobenzene, 2,3-dimethyl-1,4-diaminonaphthalene, and 4,4'-diamino-3,3'-dimethyldiphenylmethane, as well as mixtures of these isomers in various ratios,
• a nucleus-substituted alkyl group a C1-4 alkyl group such as methyl, ethyl, propyl, and butyl groups
• 2,4- or 2,6-tolylenediamine crude
• Aromatic diamines with nucleus-substituted electron-withdrawing groups halogen atoms such as fluorine, chlorine, bromine, and iodine; alkoxy groups such as methoxy and ethoxy; nitro groups, etc.
• halogen atoms such as fluorine, chlorine, bromine, and iodine
• alkoxy groups such as methoxy and ethoxy; nitro groups, etc.
• methylenebis-o-chloroaniline 4-chloro-o-phenylenediamine, 2-chloro-1,4-phenylenediamine, 3-amino-4-chloroaniline
• Aromatic diamines with secondary amino groups aromatic diamines in which part or all of the -NH2 is replaced with -NH-R' (R' is an alkyl group; for example, a lower alkyl group such as a methyl group or an ethyl group)) such as 4,4'-di(methylamino)diphenylmethane and 1-methyl-2-methylamino-4-aminobenzene,
• Polyamide polyamines low molecular weight polyamide polyamines obtained by condensation of dicarboxylic acids (dimer acids, etc.) with excess polyamines (2 moles or more per mole of acid) (the above alkylenediamines and polyalkylene polyamines, etc.),
• Examples include hydrogenated cyanoethyl compounds of polyether polyols (polyalkylene glycols, etc.), which are polyether polyamines.
• polyamidoamines and polyether polyamines are preferably used because they can form coatings with excellent strength.
• polyamines can also be used. Examples of such commercially available products include Jeffamine T-403, Jeffamine D-230, and Jeffamine D-400 (all polyether polyamines manufactured by Huntsman (USA)).
• polyether polyamines those that are preferably bifunctional or trifunctional and have a molecular weight of 200 to 5000, more preferably 200 to 1500, are preferably used.
• Non-acid-modified polyol (B3)) In the present invention, it is also preferable to use a non-acid-modified polyol (B3) in combination as a curing agent.
• non-acid-modified polyol (B3) for example, a compound having an average of two or more hydroxyl groups in the molecule can be suitably used, such as a polymer polyol selected from polyester polyol, polyether polyol, polyurethane polyol, polyether ester polyol, polyester (polyurethane) polyol, polyether (polyurethane) polyol, acrylic polyol, polycarbonate polyol, polyhydroxyl alkanes, castor oil, or a mixture thereof. Of these, it is preferable to use polyester polyol.
• Polyester polyols include, for example, dibasic acids such as terephthalic acid, isophthalic acid, phthalic anhydride, adipic acid, azelaic acid, sebacic acid, dimer acid (a liquid fatty acid containing monobasic and tribasic acids as well as C36 dibasic acids produced by dimerization of C18 unsaturated fatty acids derived from vegetable oils and fats as the main component) or their dialkyl esters or mixtures thereof, and, for example, ethylene glycol, propylene glycol, diethylene glycol, butylene glycol, neopentyl glycol, 2-methyl-1,3-propanediol, 1,6-hexanediol, 3-methyl-1,3-propanediol, 1,6-hexanediol, 1,6-methyl-1,3-propane ...
• dibasic acids such as terephthalic acid, isophthalic acid, phthalic anhydride, adip
• polyester polyols examples include polyester polyols obtained by reacting glycols such as ethyl-1,5-pentanediol, 3,3'-dimethylolheptane, polyoxyethylene glycol, polyoxypropylene glycol, and polytetramethylene ether glycol with trihydric or tetrahydric alcohols such as glycerin (glycerol), trimethylolethane, trimethylolpropane, and pentaerythritol, or mixtures thereof, and polyester polyols obtained by ring-opening polymerization of lactones such as polycaprolactone, polyvalerolactone, and poly( ⁇ -methyl- ⁇ -valerolactone).
• glycols such as ethyl-1,5-pentanediol, 3,3'-dimethylolheptane
• polyoxyethylene glycol polyoxypropylene glycol
• polytetramethylene ether glycol examples include polyte
• polyether polyols examples include polyether polyols obtained by polymerizing oxirane compounds such as ethylene oxide, propylene oxide, butylene oxide, and tetrahydrofuran with low molecular weight polyols such as water, ethylene glycol, propylene glycol, trimethylolpropane, and glycerin as an initiator.
• polyether ester polyols examples include polyether ester polyols obtained by reacting the above polyether polyols with dibasic acids such as terephthalic acid, isophthalic acid, phthalic anhydride, adipic acid, azelaic acid, sebacic acid, and dimer acid, or their dialkyl esters, or mixtures thereof.
• the polyurethane polyol is a polyol that has a urethane bond in one molecule, such as a reaction product of a polyether polyol having a number average molecular weight of 200 to 20,000 and an organic polyisocyanate, with an NCO/OH ratio of preferably less than 1, and more preferably 0.9 or less.
• the organic polyisocyanate may be a polyisocyanate compound, particularly a diisocyanate compound, as described below.
• Polyether (polyurethane) polyols and polyester (polyurethane) polyols are reaction products of polyester polyols, polyether ester polyols, etc. with organic polyisocyanates, and preferably have an NCO/OH ratio of less than 1, more preferably 0.9 or less.
• polycarbonate polyols include those obtained by reacting one or more glycols selected from ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, 1,8-nonanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, bisphenol A, and hydrogenated bisphenol A with dimethyl carbonate, diphenyl carbonate, ethylene carbonate, phosgene, etc.
• glycols selected from ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanedi
• acrylic polyols examples include those obtained by copolymerizing hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, etc., which contain one or more hydroxyl groups in one molecule, or the corresponding methacrylic acid derivatives thereof, with, for example, acrylic acid, methacrylic acid, or an ester thereof.
• the polyhydroxyalkane may be a liquid rubber obtained by copolymerizing butadiene or butadiene with acrylamide or the like.
• polyester polyols those with a number average molecular weight of 400 to 2000 and a hydroxyl value of 60 to 300 are preferably used.
• glycols such as ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, and 1,6-hexanediol, as well as trihydric or tetrahydric alcohols such as glycerin, trimethylolpropane, and pentaerythritol, can be used as they are as part of the hardener (H).
• the above non-acid-modified polyols (B3) may be used alone or in combination.
• the acid value of the curing agent (H) as a whole of the curing agent (H) containing the acid-modified polyol (B), the amine compound (C), and other compounds as necessary, is preferably in the range of 5 to 30 mgKOH/g, more preferably in the range of 10 to 20 mgKOH/g. So long as the acid value of the curing agent (H) is within the above range, the acid-modified polyol (B) and the non-acid-modified polyol (B3) may be mixed and used.
• the compounding ratio of the oil (A) containing an acid anhydride group to the hardener (H) is preferably in the range of 0.5 to 1.5, more preferably 0.8 to 1.25, in terms of the molar ratio of the acid anhydride group of the oil (A) containing an acid anhydride group to the functional group reactive with the acid anhydride group of the hardener (H) (acid anhydride group/functional group reactive with acid anhydride group). If the compounding ratio of the oil (A) containing an acid anhydride group to the hardener (H) is in the above range, a coating with excellent adhesive strength can be obtained.
• the amount of the amine compound (C) used is preferably in the range of 0.05 to 0.7, more preferably 0.1 to 0.5, in terms of the molar ratio (nitrogen/acid anhydride group) of the nitrogen of the amine compound (C) to the acid anhydride group of the oil or fat (A) containing the acid anhydride group. If the amount of the amine compound (C) used is within the above range, it is possible to obtain a cured adhesive product with excellent adhesive strength while ensuring a suitable pot life.
• Specific preferred combinations of the oil or fat (A) containing an acid anhydride group and the hardener (H) include, for example, 1) A combination of maleic anhydride-modified tung oil as the oil (A) and an acid-modified polyester polyol (B) and a tertiary amine-containing polyol (B2) as the hardener (H); 2) A combination of maleic anhydride modified soybean oil as the fat (A), an acid modified polyester polyol (B) as the hardener (H), a non-acid modified polyol (B3) and a tertiary amine-containing polyol (B2), 3)
• the vegetable oil of the fat (A) may be used in combination with a plurality of vegetable oils, such as soybean oil and tung oil.
• a catalyst may be added to the adhesive composition of the present invention.
• a catalyst include tertiary amine compounds, aliphatic cyclic amide compounds, and organometallic catalysts.
• the tertiary amine compound include diazabicycloundecene, diazabicyclononene, triethylenediamine, 2-methyltriethylenediamine, quinuclidine, and 2-methylquinuclidine.
• aliphatic cyclic amide compounds examples include ⁇ -valerolactam, ⁇ -caprolactam, ⁇ -enantholactam, ⁇ -capryllactam, and ⁇ -propiolactam.
• Organometallic catalysts include dibutyltin oxide, dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, bismuth octoate, bismuth neodecanoate, zirconium octoate, and zirconium neodecanoate.
• tertiary amine compounds are preferred due to their excellent catalytic activity.
• the adhesive composition of the present invention can be used as a solvent-based or solventless adhesive.
• the "solvent” of the solventless adhesive in the present invention refers to a highly soluble organic solvent capable of dissolving the polyisocyanate compound and polyol compound used in the present invention, and “solventless” refers to the absence of these highly soluble organic solvents.
• highly soluble organic solvents include toluene, xylene, methylene chloride, tetrahydrofuran, methanol, ethanol, isopropyl alcohol, methyl acetate, ethyl acetate, n-butyl acetate, acetone, methyl ethyl ketone (MEK), cyclohexanone, toluene, xylol, n-hexane, and cyclohexane.
• MEK methyl ethyl ketone
• toluene, xylene, methylene chloride, tetrahydrofuran, methyl acetate, and ethyl acetate are known as organic solvents with particularly high solubility.
• the adhesive of the present invention may be diluted with the organic solvent having high solubility as appropriate according to the desired viscosity.
• the oil having an acid anhydride group (A) or the hardener (H) may be diluted, or both may be diluted.
• organic solvents used in such cases include methanol, ethanol, isopropyl alcohol, methyl acetate, ethyl acetate, n-butyl acetate, acetone, methyl ethyl ketone (MEK), cyclohexanone, toluene, xylol, n-hexane, and cyclohexane.
• ethyl acetate and methyl ethyl ketone (MEK) are preferred from the viewpoint of solubility, and ethyl acetate is particularly preferred.
• the amount of organic solvent used depends on the required viscosity, but is often in the range of about 20 to 50% by mass.
• the adhesive composition of the present invention may be used in combination with a pigment, if necessary.
• the pigment that can be used is not particularly limited, and examples thereof include organic pigments and inorganic pigments such as extender pigments, white pigments, black pigments, gray pigments, red pigments, brown pigments, green pigments, blue pigments, metal powder pigments, luminescent pigments, and pearlescent pigments, as well as plastic pigments, which are listed in the Paint Raw Materials Handbook 1970 edition (edited by the Japan Paint Manufacturers Association). Specific examples of these colorants include various ones.
• organic pigments include various insoluble azo pigments such as Benzidine Yellow, Hansa Yellow, Lake 4R, etc.; soluble azo pigments such as Lake C, Carmine 6B, Bordeaux 10, etc.; various (copper) phthalocyanine pigments such as Phthalocyanine Blue, Phthalocyanine Green, etc.; various chlorine dyeing lakes such as Rhodamine Lake, Methyl Violet Lake, etc.; various mordant dye pigments such as Quinoline Lake, Fast Sky Blue, etc.; various vat dye pigments such as Anthraquinone pigments, Thioindigo pigments, Perinone pigments, etc.; various quinacridone pigments such as Synchasia Red B, etc.; various dioxazine pigments such as Dioxazine Violet, etc.; various condensed azo pigments such as Chromophtal, etc.; aniline black, etc.
• insoluble azo pigments such as Benzidine Yellow, Hansa Yellow, Lake 4R, etc.
• Inorganic pigments include, for example, various chromates such as yellow lead, zinc chromate, and molybdate orange; various ferrocyanide compounds such as Prussian blue; various metal oxides such as titanium oxide, zinc oxide, mapico yellow, iron oxide, red iron oxide, chrome oxide green, and zirconium oxide; various sulfides or selenides such as cadmium yellow, cadmium red, and mercury sulfide; various sulfates such as barium sulfate and lead sulfate; various silicates such as calcium silicate and ultramarine; various carbonates such as calcium carbonate and magnesium carbonate; various phosphates such as cobalt violet and manganese purple; various metal powder pigments such as aluminum powder, gold powder, silver powder, copper powder, bronze powder, and brass powder; flake pigments of these metals, mica flake pigments; metallic pigments and pearl pigments such as mica flake pigments coated with metal oxides and micaceous iron oxide pigments; graphite, carbon black,
• extender pigments include precipitated barium sulfate, powdered gourd, precipitated calcium carbonate, calcium bicarbonate, kansui stone, white alumina, silica, finely powdered hydrous silica (white carbon), ultrafine anhydrous silica (aerosil), silica sand, talc, precipitated magnesium carbonate, bentonite, clay, kaolin, and yellow earth.
• plastic pigments examples include “Grandol PP-1000” and “PP-2000S” manufactured by DIC Corporation.
• the pigments used in the present invention are preferably inorganic oxides such as titanium oxide and zinc oxide as white pigments, and carbon black as black pigments, because they have excellent durability, weather resistance, and design properties.
• the mass ratio of the pigment used in the present invention is 1 to 400 parts by mass, and more preferably 10 to 300 parts by mass, per 100 parts by mass of the solid content of the adhesive composition of the present invention, as this provides excellent adhesion, blocking resistance, etc.
• the adhesive composition used in the present invention may also contain an adhesion promoter, such as a silane coupling agent, a titanate coupling agent, an aluminum coupling agent, or an epoxy resin.
• an adhesion promoter such as a silane coupling agent, a titanate coupling agent, an aluminum coupling agent, or an epoxy resin.
• Silane coupling agents include, for example, aminosilanes such as ⁇ -aminopropyltriethoxysilane, ⁇ -aminopropyltrimethoxysilane, N- ⁇ (aminoethyl)- ⁇ -aminopropyltrimethoxysilane, N- ⁇ (aminoethyl)- ⁇ -aminopropyltrimethyldimethoxysilane, and N-phenyl- ⁇ -aminopropyltrimethoxysilane; epoxysilanes such as ⁇ -(3,4-epoxycyclohexyl)ethyltrimethoxysilane, ⁇ -glycidoxypropyltrimethoxysilane, and ⁇ -glycidoxypropyltriethoxysilane; vinylsilanes such as vinyltris( ⁇ -methoxyethoxy)silane, vinyltriethoxysilane, vinyltrimethoxysilane, and ⁇ -me
• Titanate coupling agents include, for example, tetraisopropoxytitanium, tetra-n-butoxytitanium, butyl titanate dimer, tetrastearyl titanate, titanium acetylacetonate, titanium lactate, tetraoctylene glycol titanate, titanium lactate, and tetrastearoxytitanium.
• examples of aluminum-based coupling agents include acetoalkoxyaluminum diisopropylate.
• Epoxy resins include epoxidized oils and fats, such as epoxidized soybean oil, which is generally available on the market; various epoxy resins such as epibis type, novolac type, ⁇ -methyl epichlorohydrin type, cyclic oxirane type, glycidyl ether type, glycidyl ester type, polyglycol ether type, glycol ether type, epoxidized fatty acid ester type, polyvalent carboxylic acid ester type, aminoglycidyl type, and resorcinol type; and compounds such as triglycidyl tris(2-hydroxyethyl)isocyanurate, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, acrylic glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, phenol glycidyl
• additives that can be used in addition to those mentioned above include leveling agents, inorganic fine particles such as colloidal silica and alumina sol, polymethyl methacrylate-based organic fine particles, defoamers, anti-sagging agents, wetting and dispersing agents, viscosity adjusters, UV absorbers, metal deactivators, peroxide decomposers, flame retardants, reinforcing agents, plasticizers, lubricants, rust inhibitors, fluorescent brighteners, inorganic heat absorbers, flame retardants, antistatic agents, dehydrating agents, known and commonly used thermoplastic elastomers, tackifiers, phosphate compounds, melamine resins, or reactive elastomers.
• the content of these additives can be adjusted appropriately within a range that does not impair the function of the adhesive composition used in the present invention.
• additives can be mixed into either the oil or fat containing an acid anhydride group (A) or the hardener (H), or can be used as a third component when applied.
• the laminate of the present invention is a laminate obtained by laminating a first substrate, an adhesive layer, and a second substrate in this order. Specifically, the laminate is obtained by bonding the first substrate, which is a film, paper, or the like, and the second substrate using the adhesive of the present invention by a dry lamination method or a non-solvent lamination method.
• the first substrate and the second substrate can be appropriately selected according to the desired application without any particular limitation, but the adhesive of the present invention can maximize its effect when they are plastic films.
• plastic films are mainly used as substrates for packaging materials for food, medicines, detergents, etc., which are the main applications of the present invention.
• these plastic films may be appropriately provided with layers according to the desired application, such as a vapor deposition layer of a metal such as aluminum or a metal oxide such as silica or alumina, a functional coating layer, a printed layer, or a primer layer for facilitating the provision of a printed layer or a vapor deposition layer.
• a laminate using a reactive adhesive other than the adhesive of the present invention may be used, but may have poor recyclability.
• the film is not particularly limited, and a film can be appropriately selected according to the application.
• polyolefin films such as polyethylene terephthalate (PET) film, polystyrene film, polyamide film, polyacrylonitrile film, polyethylene film (LLDPE: low density polyethylene film, HDPE: high density polyethylene film) and polypropylene film (CPP: non-oriented polypropylene film, OPP: biaxially oriented polypropylene film), polyvinyl alcohol film, ethylene-vinyl alcohol copolymer film, etc.
• PET polyethylene terephthalate
• polystyrene film polyamide film
• polyacrylonitrile film polyethylene film
• LLDPE low density polyethylene film
• HDPE high density polyethylene film
• polypropylene film CPP: non-oriented polypropylene film
• OPP biaxially oriented polypropylene film
• polyvinyl alcohol film ethylene-vinyl alcohol copolymer film, etc.
• the film may be one that has been stretched.
• a typical stretching method involves melt-extruding a resin into a sheet using an extrusion film-making method or the like, followed by simultaneous biaxial stretching or sequential biaxial stretching.
• sequential biaxial stretching it is common to first perform longitudinal stretching, and then transverse stretching. Specifically, a method that combines longitudinal stretching using the speed difference between rolls and transverse stretching using a tenter is often used.
• a film laminated with a vapor-deposited layer of a metal such as aluminum or a metal oxide such as silica or alumina, or a barrier film containing a gas barrier layer such as polyvinyl alcohol, ethylene-vinyl alcohol copolymer, or vinylidene chloride may be used in combination.
• a gas barrier layer such as polyvinyl alcohol, ethylene-vinyl alcohol copolymer, or vinylidene chloride
• the film surface may be subjected to various surface treatments such as flame treatment or corona discharge treatment to ensure that an adhesive layer is formed that is free of defects such as film breaks or repellency.
• the laminate of the present invention can be obtained by applying the adhesive of the present invention as an adhesive auxiliary (anchor coating agent) to a film using a laminator, carrying out a curing reaction, and then laminating a polymer material molten using an extruder (extrusion lamination method).
• the film that can be used is the same as the film used in the dry lamination method and non-solvent lamination method described above.
• the polymer material to be melted is preferably a polyolefin resin such as low-density polyethylene resin, linear low-density polyethylene resin, or ethylene-vinyl acetate copolymer resin.
• the laminate has the following structure: (1) Base film 1/adhesive layer 1/sealant film (2) Base film 1/adhesive layer 1/metal-vapor-deposited unstretched film (3) Base film 1/adhesive layer 1/metal-vapor-deposited stretched film (4) Transparent vapor-deposited stretched film/adhesive layer 1/sealant film (5) Base film 1/adhesive layer 1/base film 2/adhesive layer 2/sealant film (6) Base film 1/adhesive layer 1/metal-vapor-deposited stretched film/adhesive layer 2/sealant film (7) Base film 1/adhesive layer 1/transparent vapor-deposited stretched film/adhesive layer 2/sealant film (8) Base film 1/adhesive layer 1/metal layer/adhesive layer 2/sealant film (9) Base film 1/adhesive layer 1/base film 2/adhesive layer (9)
• the base film 1 used in the structure (1) may be an OPP film, a PET film, a nylon film, or the like.
• the base film 1 may be coated with a coating for the purpose of improving the gas barrier properties or the ink receptivity when a printing layer is provided, as described below.
• Examples of commercially available coated base films 1 include K-OPP film and K-PET film.
• the adhesive layer 1 is a cured coating of the adhesive of the present invention.
• sealant films include CPP film and LLDPE film.
• a printing layer, as described below, may be provided on the surface of the base film 1 on the adhesive layer 1 side (when a coated base film 1 is used, the surface of the coating layer on the adhesive layer 1 side).
• the printing layer is formed by a general printing method that has been used for printing on polymer films using various printing inks such as gravure ink, flexo ink, offset ink, stencil ink, and inkjet ink.
• the base film 1 used in structures (2) and (3) may be an OPP film or a PET film.
• the adhesive layer 1 is a cured coating of the adhesive of the present invention.
• a metal-vapor-deposited unstretched film a VM-CPP film obtained by depositing a metal such as aluminum on a CPP film may be used, and as a metal-vapor-deposited stretched film, a VM-OPP film obtained by depositing a metal such as aluminum on an OPP film may be used.
• a printed layer which will be described later, may be provided on the adhesive layer 1 side of the base film 1.
• the transparent vapor-deposited stretched film used in configuration (4) may be an OPP film, a PET film, a nylon film, or the like, on which silica or alumina has been vapor-deposited.
• a film on which a coating has been applied to the vapor-deposited layer of silica or alumina may be used for the purpose of protecting the inorganic vapor-deposited layer.
• the adhesive layer 1 is a cured coating of the adhesive of the present invention. Examples of the sealant film include the same as those in configuration (1).
• a printed layer may be provided on the surface of the transparent vapor-deposited stretched film on the adhesive layer 1 side (when a film on which a coating has been applied to the inorganic vapor-deposited layer is used, the surface of the coating layer on the adhesive layer 1 side).
• the method of forming the printed layer is the same as in configuration (1).
• the base film 1 used in structure (5) may be a PET film or the like.
• the base film 2 may be a nylon film or the like.
• At least one of the adhesive layer 1 and the adhesive layer 2 is a cured coating film of the adhesive of the present invention.
• the sealant film may be the same as that in structure (1).
• a printing layer which will be described later, may be provided on the surface of the base film 1 on the adhesive layer 1 side.
• the base film 1 in structure (6) may be the same as those in structures (2) and (3).
• Metal-vapor-deposited stretched films include VM-OPP films and VM-PET films in which a metal such as aluminum is vapor-deposited on an OPP film or a PET film.
• At least one of the adhesive layer 1 and the adhesive layer 2 is a cured coating film of the adhesive of the present invention.
• the sealant film may be the same as those in structure (1).
• a printed layer described below, may be provided on the surface of the base film 1 on the adhesive layer 1 side.
• the base film 1 in structure (7) may be a PET film or the like.
• the transparent vapor deposition stretched film may be the same as that in structure (4).
• At least one of the adhesive layers 1 and 2 is a cured coating film of the adhesive of the present invention.
• the sealant film may be the same as that in structure (1).
• a printed layer which will be described later, may be provided on the surface of the base film 1 on the adhesive layer 1 side.
• the base film 1 in structure (8) may be a PET film or the like.
• the metal layer may be an aluminum foil or the like.
• At least one of the adhesive layers 1 and 2 is a cured coating film of the adhesive of the present invention.
• the sealant film may be the same as that in structure (1).
• a printed layer which will be described later, may be provided on the surface of the base film 1 on the adhesive layer 1 side.
• the base film 1 may be a PET film or the like.
• the base film 2 may be a nylon film or the like.
• the metal layer may be an aluminum foil or the like.
• At least one of the adhesive layers 1, 2, and 3 is a cured coating film of the adhesive of the present invention.
• the sealant film may be the same as in structure (1).
• a printed layer which will be described later, may be provided on the surface of the base film 1 on the adhesive layer 1 side.
• the adhesive layer in contact with the metal vapor deposition layer, the transparent vapor deposition layer, and the metal layer is a cured coating film of the adhesive of the present invention.
• the adhesive of the present invention is usually used as a two-liquid adhesive. Therefore, it is preferable to mix the oil (A) containing an acid anhydride group with the curing agent (H) immediately before use.
• the compounding ratio is preferably in the range of 0.5 to 1.5, more preferably 0.8 to 1.25, in terms of the molar ratio of the acid anhydride group of (A) to the functional group reactive with the acid anhydride group of (H) (acid anhydride group/functional group reactive with acid anhydride group). If the compounding ratio of (A) to (H) is within the above range, a coating having excellent adhesive strength can be obtained.
• the amount of (C) used is preferably in the range of 0.05 to 0.7, more preferably 0.1 to 0.5, in terms of the molar ratio of the nitrogen of (C) to the acid anhydride group of (A) (nitrogen/acid anhydride group). If the amount of (C) used is within the above range, an adhesive cured product having excellent adhesive strength can be obtained while ensuring a suitable pot life.
• the oil or fat containing an acid anhydride group (A) may be expressed as the main component, and the hardener (H) as the hardener.
• the adhesive of the present invention is a solvent-based adhesive
• the adhesive of the present invention is applied to a film material that serves as a substrate using a roll such as a gravure roll, and the organic solvent is evaporated by heating in an oven or the like, and then the other substrate is laminated to obtain the laminate of the present invention.
• a roll such as a gravure roll
• the organic solvent is evaporated by heating in an oven or the like
• the other substrate is laminated to obtain the laminate of the present invention.
• After lamination it is preferable to carry out an aging treatment.
• the aging temperature is preferably room temperature to 80°C
• the aging time is preferably 12 to 240 hours.
• the adhesive of the present invention is a solventless type
• the adhesive of the present invention which has been preheated to about 40°C to 100°C, is applied to the film material that will serve as the substrate using a roll such as a gravure roll, and the other substrate is immediately laminated to obtain the laminate of the present invention.
• a roll such as a gravure roll
• the other substrate is immediately laminated to obtain the laminate of the present invention.
• an aging treatment is preferably room temperature to 70°C, and the aging time is preferably 6 to 240 hours.
• the adhesive auxiliary of the present invention is applied to the base film material using a roll such as a gravure roll, the organic solvent is evaporated by heating in an oven or the like, and then a molten polymer material is laminated using an extruder to obtain the laminate of the present invention.
• the amount of adhesive applied is adjusted appropriately.
• the amount of solids is adjusted to, for example, 1 g/ m2 to 10 g/ m2 , preferably 1 g/ m2 to 5 g/ m2 .
• the amount of adhesive applied is, for example, 1 g/ m2 to 10 g/ m2 , preferably 1 g/ m2 to 5 g/ m2 .
• the coating amount is, for example, 0.03 g/m 2 or more and 0.09 g/m 2 or less (solid content).
• the printing layer is a layer on which characters, figures, symbols, and other desired patterns are printed.
• the printing method or printing ink there is no particular limitation on the printing method or printing ink, and any known printing method or printing ink can be used.
• Printing inks using gravure printing, flexographic printing, lithographic offset printing, inkjet recording printing, and the like are often used for the film used as the substrate.
• Printing inks that combine these printing methods with a method of curing with active energy rays such as ultraviolet rays (UV), LEDs, and electron beams (EB), or a method of curing with heat, etc. are also used.
• active energy rays such as ultraviolet rays (UV), LEDs, and electron beams (EB), or a method of curing with heat, etc.
• UV ultraviolet rays
• EB electron beams
• heat heat
• gravure printing ink and flexographic printing ink in some industries, gravure printing ink and flexographic printing ink are referred to as liquid printing ink
• UV-curable ink for lithographic offset printing in some industries, gravure printing ink and flexographic printing ink are referred to as liquid printing ink
• electron beam curable ink for lithographic offset printing in some industries, UV-curable ink for inkjet recording and printing
• electron beam curable ink for inkjet recording and printing include electron beam curable ink for inkjet recording and printing.
• liquid ink such as gravure ink or flexographic ink.
• the laminate may be provided at any position.
• liquid ink is a general term for solvent-based ink used in gravure printing or flexographic printing. It may contain resin, colorant, and solvent as essential components, or it may be a so-called clear ink that contains resin and solvent but does not substantially contain colorant.
• the resins used in the liquid ink are not particularly limited, and examples include acrylic resin, polyester resin, styrene resin, styrene-maleic acid resin, maleic acid resin, polyamide resin, polyurethane resin, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-acrylic copolymer resin, ethylene-vinyl acetate copolymer resin, vinyl acetate resin, polyvinyl chloride resin, chlorinated polypropylene resin, cellulose-based resin, epoxy resin, alkyd resin, rosin-based resin, rosin-modified maleic acid resin, ketone resin, cyclized rubber, chlorinated rubber, butyral, petroleum resin, etc., and one or more of these can be used in combination.
• at least one or two or more selected from polyurethane resin, vinyl chloride-vinyl acetate copolymer resin, and cellulose-based resin are used.
• Colorants used in liquid inks include inorganic pigments such as titanium oxide, red iron oxide, antimony red, cadmium red, cadmium yellow, cobalt blue, Prussian blue, ultramarine blue, carbon black, and graphite; organic pigments such as soluble azo pigments, insoluble azo pigments, azo lake pigments, condensed azo pigments, copper phthalocyanine pigments, and condensed polycyclic pigments; and extender pigments such as calcium carbonate, kaolin clay, barium sulfate, aluminum hydroxide, and talc.
• inorganic pigments such as titanium oxide, red iron oxide, antimony red, cadmium red, cadmium yellow, cobalt blue, Prussian blue, ultramarine blue, carbon black, and graphite
• organic pigments such as soluble azo pigments, insoluble azo pigments, azo lake pigments, condensed azo pigments, copper phthalocyanine pigments, and condensed polycyclic pigment
• the organic solvent used in the liquid ink preferably does not contain aromatic hydrocarbon organic solvents. More specifically, examples of the organic solvents include alcohol organic solvents such as methanol, ethanol, n-propanol, isopropanol, and butanol; ketone organic solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ester organic solvents such as methyl acetate, ethyl acetate, propyl acetate, and butyl acetate; aliphatic hydrocarbon organic solvents such as n-hexane, n-heptane, and n-octane; and alicyclic hydrocarbon organic solvents such as cyclohexane, methylcyclohexane, ethylcyclohexane, cycloheptane, and cyclooctane. These can be used alone or in combination of two or more.
• a primer layer can be provided to facilitate fixation of the printed layer to the plastic film substrate and to facilitate peeling of the printed layer in a treatment using an alkaline solution, which is currently the most widely used recycling treatment.
• a primer layer containing a urethane resin is particularly preferred as the primer layer.
• the urethane resin (PA) suitable for the primer layer used in the present invention is made of a reaction product obtained by reacting (crosslinking/curing reaction) an aromatic polyester polyol (a1) with a polyisocyanate (a2).
• the urethane resin (PA) may contain, in addition to the aromatic polyester polyol (a1) and the polyisocyanate (a2), another polyol (a3), or may be a reaction product of the aromatic polyester polyol (a1), the polyisocyanate (a2), and the other polyol (a3).
• the aromatic polyester polyol (a1) can be produced, for example, by subjecting an aromatic dicarboxylic acid (a1-1) and a polyol (a1-2) to an esterification reaction.
• Aromatic dicarboxylic acids (a1-1) that can be used in producing aromatic polyester polyol (a1) include, for example, aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, and 1,2-bis(phenoxy)ethane-P,P'-dicarboxylic acid, as well as their acid anhydrides or ester-forming derivatives; aromatic hydroxycarboxylic acids such as p-hydroxybenzoic acid, as well as their ester-forming derivatives; and sulfonic acid group-containing aromatic dicarboxylic acids such as 5-sulfoisophthalic acid, as well as their ester-forming derivatives.
• aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid,
• an aliphatic carboxylic acid or an alicyclic carboxylic acid can be used in combination.
• examples include aliphatic dicarboxylic acids such as succinic acid, succinic anhydride, adipic acid, suberic acid, azelaic acid, sebacic acid, dimer acid, maleic anhydride, and fumaric acid, and alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, and their anhydrides or ester-forming derivatives. These may be used alone or in combination of two or more.
• polyol (a1-2) for example, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexanediol, 2,5-hexanediol, 1,6-hexanediol, 1,7-heptanediol, neopentyl glycol, etc. can be used.
• aromatic dicarboxylic acid (a1-1) and polyol (a1-2) can be reacted in the presence of a catalyst as necessary in a reaction vessel purged with an inert gas such as nitrogen under normal or reduced pressure.
• the reaction is preferably carried out in the range of 100°C to 300°C.
• the catalyst for example, acetates of alkali metals or alkaline earth metals, or compounds containing zinc, manganese, cobalt, antimony, germanium, titanium, tin, zirconium, etc. can be used. Among them, it is preferable to use tetraalkyl titanates or tin oxalate, which are effective for transesterification reactions and polycondensation reactions.
• the aromatic polyester polyol (a1) and the polyisocyanate (a2) can also be used in combination with other polyols (a3), etc.
• polyols (a3) that can be used include polyols similar to the polyols (a1-2) above, such as relatively low molecular weight polyols such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexanediol, 2,5-hexanediol, 1,6-hexanediol, 1,7-heptanediol, and neopentyl glycol.
• relatively low molecular weight polyols such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol, 1,4-butaned
• polyisocyanate (a2) As the polyisocyanate (a2) that reacts with the polyol (a1) to form the urethane resin (PA), for example, aromatic diisocyanates such as phenylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, and naphthalene diisocyanate, and aliphatic or aliphatic cyclic structure-containing diisocyanates such as hexamethylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, xylylene diisocyanate, and tetramethylxylylene diisocyanate can be used alone or in combination of two or more.
• aromatic diisocyanates such as phenylene diisocyanate, tolylene diisocyanate, diphenylmethane di
• the viewpoint of improving the adhesion to the substrate and the deinking property of the resulting primer layer it is more preferable to use one or more selected from the group consisting of isophorone diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate, and dicyclohexylmethane diisocyanate from the viewpoint of improving the adhesion to the substrate and the deinking property of the resulting primer layer.
• the urethane resin (PA) can be produced, for example, in the absence of a solvent or in the presence of an organic solvent, by reacting the aromatic polyester polyol (a1), the polyisocyanate (a2), and, if necessary, the polyol (a3), and, if necessary, a chain extender.
• the organic solvent it is preferable to remove the organic solvent by a method such as distillation, as necessary, when dispersing the urethane resin (PA) in the aqueous medium (S).
• Organic solvents that can be used when producing urethane resin (PA) include, for example, ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran and dioxane; acetates such as ethyl acetate and butyl acetate; nitriles such as acetonitrile; dimethylformamide and N-methylpyrrolidone, which can be used alone or in combination of two or more.
• the chain extender that can be used when producing the urethane resin (PA) can be used for the purpose of increasing the molecular weight of the urethane resin (PA) and improving the durability of the resulting film or the like.
• a chain extender that can be used when producing the urethane resin (PA) polyamines and other compounds containing active hydrogen atoms can be used.
• polyamines examples include diamines such as ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2,5-dimethylpiperazine, isophoronediamine, 4,4'-dicyclohexylmethanediamine, 3,3'-dimethyl-4,4'-dicyclohexylmethanediamine, and 1,4-cyclohexanediamine; N-hydroxymethylaminoethylamine, N-hydroxyethylaminoethylamine, N-hydroxypropylaminopropylamine, N-ethylaminoethylamine, and N-methylaminopropylamine; It is possible to use ethylenetriamine, dipropylenetriamine, triethylenetetramine; hydrazine, N,N'-dimethylhydrazine, 1,6-hexamethylenebishydrazine; succinic acid dihydrazide, adipic acid dihydrazide, glutaric
• active hydrogen-containing compounds that can be used include, for example, glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, hexamethylene glycol, neopentyl glycol, sucrose, methylene glycol, glycerin, and sorbitol; phenols such as bisphenol A, 4,4'-dihydroxydiphenyl, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl sulfone, hydrogenated bisphenol A, and hydroquinone; and water.
• glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, hexamethylene glycol, neopent
• the concentration of aromatic rings derived from raw material monomers of the aromatic dicarboxylic acid (a1-1) in the urethane resin (PA) is 1 mmol/g or more.
• the aromatic ring concentration can be determined by calculating the number of moles of aromatic rings contained in 1 g of the urethane resin (PA). The specific calculation method will be described later.
• the aromatic ring concentration is preferably 1.5 mmol/g or more, and more preferably 2 mmol/g or more, and from the viewpoint of good film-forming properties of the primer layer, the aromatic ring concentration is preferably 6 mmol/g or less, and more preferably 5 mmol/g or less.
• the ester bond concentration in the urethane resin (PA) is 1 mmol/g or more.
• the ester bond concentration is determined by calculating the number of moles of the ester bond groups contained in 1 g of the urethane resin (PA). The specific calculation method will be described later.
• the ester bond group concentration is preferably 2 mmol/g or more, and more preferably 4 mmol/g or more, and from the viewpoint of good blocking resistance of the primer layer, the ester bond group concentration is preferably 9 mmol/g or less, and more preferably 7 mmol/g or less.
• the value obtained by dividing the mass of the raw material monomer of the polyisocyanate (a2) contained in 1 g of the urethane resin (PA) by the NCO equivalent weight of the raw material monomer of the polyisocyanate (a2) is preferably 1.0 to 6.0 mmol/g. If the value is 1.0 mmol/g or more, the substrate adhesion and deinking property of the obtained primer layer can be improved, and the value is more preferably 1.5 mmol/g or more, and more preferably 1.8 mmol/g or more. If the value is 6.0 mmol/g or less, the film-forming property of the primer layer can be ensured, and the value is more preferably 5.0 mmol/g or less, and more preferably 4.0 mmol/g or less.
• the weight average molecular weight of the urethane resin (PA) is preferably 10,000 to 100,000. From the viewpoints of blocking resistance to the substrate and hydrolysis stability of the resin, the weight average molecular weight of the urethane resin (PA) is preferably 20,000 or more, and more preferably 30,000 or more. Also, from the viewpoints of low viscosity during aqueous dispersion and productivity, the weight average molecular weight is preferably 80,000 or less, and more preferably 60,000 or less.
• the weight average molecular weight refers to a value measured by gel permeation chromatography (GPC) under the following conditions.
• Measurement device High-speed GPC device ("HLC-8220GPC” manufactured by Tosoh Corporation) Column: The following columns manufactured by Tosoh Corporation were used in series connection.
• “TSKgel G5000” (7.8mm I.D. x 30cm) x 1 "TSKgel G4000” (7.8mm I.D. x 30cm) x 1 "TSKgel G3000” (7.8mm I.D. x 30cm) x 1 "TSKgel G2000" (7.8mm I.D.
• the glass transition temperature of the urethane resin (PA) is preferably 0 to 110°C.
• the urethane resin (PA) is preferably present in an aqueous medium.
• the aqueous medium (S) serving as a solvent includes water, organic solvents miscible with water, and mixtures thereof.
• organic solvents that are miscible with water include alcohols such as methanol, ethanol, n- and isopropanol; ketones such as acetone and methyl ethyl ketone; polyalkylene glycols such as ethylene glycol, diethylene glycol, and propylene glycol; alkyl ethers of polyalkylene glycol; and N-methyl-2-pyrrolidone.
• only water may be used, or a mixture of water and an organic solvent miscible with water may be used, or only an organic solvent miscible with water may be used. From the viewpoint of safety and environmental load, only water or a mixture of water and an organic solvent miscible with water is preferred, and only water is particularly preferred.
• a machine such as a homogenizer can be used as necessary.
• the aqueous urethane resin composition suitable for the primer layer used in the present invention preferably contains urethane resin (PA) in the range of 5% by mass to 50% by mass, and more preferably 10% by mass to 25% by mass, based on the total amount of the aqueous urethane resin composition.
• the aqueous medium (S) is preferably contained in the range of 50% by mass to 95% by mass, and more preferably 75% by mass to 90% by mass, based on the total amount of the urethane resin composition.
• the aqueous urethane resin composition suitable for the primer layer used in the present invention may contain various additives, such as a film-forming assistant, a crosslinking agent, a curing accelerator, a plasticizer, an antistatic agent, a wax, a light stabilizer, a flow regulator, a dye, a leveling agent, a rheology control agent, an ultraviolet absorber, an antioxidant, a photocatalytic compound, an inorganic pigment, an organic pigment, and an extender pigment, as required.
• various additives such as a film-forming assistant, a crosslinking agent, a curing accelerator, a plasticizer, an antistatic agent, a wax, a light stabilizer, a flow regulator, a dye, a leveling agent, a rheology control agent, an ultraviolet absorber, an antioxidant, a photocatalytic compound, an inorganic pigment, an organic pigment, and an extender pigment, as required.
• emulsifiers and leveling agents can cause a decrease in the durability of the resulting film, etc., so when high durability is required for the film, etc., it is preferable to use them in an amount of 5 mass% or less based on the total amount of the aqueous urethane resin composition.
• the aqueous urethane resin composition suitable for the primer layer used in the present invention can be used in combination with various crosslinking agents to form a film with excellent durability, etc.
• the crosslinking agent that can be used include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, amino-based crosslinking agents, aziridine-based crosslinking agents, silane coupling agent-based crosslinking agents, carbodiimide-based crosslinking agents, and oxazolidine-based crosslinking agents.
• the aqueous urethane resin composition suitable for the primer layer used in the present invention can be applied onto the above-mentioned substrate to form a primer layer.
• the aqueous urethane resin composition of the present invention can be applied to a substrate by using a known printing method such as gravure printing, flexographic printing, etc.
• the composition is diluted with an aqueous solution, for example, a diluting solvent obtained by mixing water with an alcohol-based organic solvent such as ethyl alcohol, isopropyl alcohol, or normal propyl alcohol, to a viscosity and concentration suitable for the gravure printing method or the flexographic printing method, and is supplied to each printing unit either alone or in a mixture.
• the laminate of the present invention can be suitably used for a variety of applications, such as packaging materials for food, medicines, and daily necessities; lid materials, paper tableware such as paper straws, paper napkins, paper spoons, paper plates, and paper cups; barrier materials, roofing materials, solar panel materials, battery packaging materials, window materials, outdoor flooring materials, lighting protection materials, automotive parts, signs, stickers, and other outdoor industrial applications; decorative sheets used in simultaneous injection molding decoration methods, and packaging materials for liquid laundry detergents, liquid kitchen detergents, liquid bath detergents, liquid bath soaps, liquid shampoos, liquid conditioners, and the like.
• the laminate of the present invention can be used as a multi-layer packaging material for protecting foods, medicines, etc.
• the layer structure can be changed depending on the contents, the environment of use, and the form of use.
• the packaging material of the present invention may be appropriately provided with an easy-opening treatment or a resealable means.
• the packaging material of the present invention is obtained by using the laminate of the present invention, overlapping the faces of the sealant film of the laminate so that they face each other, and then heat-sealing the peripheral edge to form a bag.
• the bag-making method include folding or overlapping the laminate of the present invention so that the faces of the inner layers (the faces of the sealant film) face each other, and heat-sealing the peripheral edge, for example, by using a side seal type, a two-sided seal type, a three-sided seal type, a four-sided seal type, an envelope seal type, a grooving seal type, a pleated seal type, a flat-bottom seal type, a square-bottom seal type, a gusset type, or other heat seal type.
• the packaging material of the present invention can take various forms depending on the contents, the environment in which it is used, and the form in which it is used. Self-supporting packaging materials (standing pouches) are also possible. Heat sealing can be performed by known methods such as bar seal, rotary roll seal, belt seal, impulse seal, high-frequency seal, and ultrasonic seal.
• the packaging material of the present invention is filled with the contents through its opening, and the opening is then heat-sealed to produce a product using the packaging material of the present invention.
• the contents to be filled include, for example, foods such as rice crackers, bean snacks, nuts, biscuits and cookies, wafer snacks, marshmallows, pies, semi-dried cakes, candies, and snack foods; staple foods such as bread, snack noodles, instant noodles, dried noodles, pasta, aseptically packaged cooked rice, porridge, porridge, packaged rice cakes, and cereal foods; processed agricultural products such as pickles, boiled beans, natto, miso, frozen tofu, tofu, nametake mushrooms, konjac, wild vegetable products, jams, peanut cream, salads, frozen vegetables, and potato products; processed livestock products such as ham, bacon, sausages, processed chicken products, and corned beef; and fish ham, These include sausages, fish paste products, fish cakes, nori, tsukudani (food boiled in soy sauce), dried bonito flakes,
• non-food items including tobacco, disposable hand warmers, medicines such as infusion packs, liquid laundry detergent, liquid kitchen detergent, liquid bath detergent, liquid bath soap, liquid shampoo, liquid conditioner, cosmetics such as lotion and milky lotion, vacuum insulation materials, batteries, etc.
• the laminate of the present invention can be separated into its respective substrates and recovered by treatment using an alkaline solution, which is currently the most widely used recycling treatment.
• the laminate can be immersed in an alkaline solution while being heated and stirred at 20 to 90° C., whereby the laminate can be separated and recovered.
• the alkaline solution used in the separation and recovery method is preferably an aqueous sodium hydroxide solution, an aqueous potassium hydroxide solution, or the like.
• the aqueous sodium hydroxide solution or the aqueous potassium hydroxide solution is preferably an aqueous solution with a concentration of 0.5% by mass to 10% by mass, and more preferably an aqueous solution with a concentration of 1% by mass to 5% by mass.
• the pH is preferably 10 or higher.
• the alkaline solution may also contain a water-soluble organic solvent.
• the water-soluble organic solvent include methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, ethylene glycol monomethyl ether (methyl cellosolve), ethylene glycol monoethyl ether (cellosolve), ethylene glycol monobutyl ether (butyl cellosolve), ethylene glycol dibutyl ether, diethylene glycol monomethyl ether (methyl carbitol), diethylene glycol dimethyl ether, diethylene glycol monoethyl ether (carbitol), diethylene glycol diethyl ether (diethyl carbitol), diethylene glycol monobutyl ether (butyl carbitol), diethylene glycol dibutyl ether, and triethylene glycol.
• Examples include ethylene glycol monomethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, methylene dimethyl ether (methylal), propylene glycol monobutyl ether, tetrahydrofuran, acetone, diacetone alcohol, acetonylacetone, acetylacetone, ethylene glycol monomethyl ether acetate (methyl cellosolve acetate), diethylene glycol monomethyl ether acetate (methyl carbitol acetate), diethylene glycol monoethyl ether acetate (carbitol acetate), ethyl hydroxyisobutyrate and ethyl lactate, which may be used alone or in combination of two or more.
• the content of the water-soluble organic solvent in the alkaline solution is preferably 30% by mass to 70% by mass, and more preferably 40% by mass to 60% by mass.
• the alkaline solution may also contain a water-insoluble organic solvent.
• the water-insoluble organic solvent include alcohol-based solvents such as n-butanol, 2-butanol, isobutanol, and octanol; aliphatic hydrocarbon-based solvents such as hexane, heptane, and normal paraffin; aromatic hydrocarbon-based solvents such as benzene, toluene, xylene, and alkylbenzene; halogenated hydrocarbon-based solvents such as methylene chloride, 1-chlorobutane, 2-chlorobutane, 3-chlorobutane, and carbon tetrachloride; ester-based solvents such as methyl acetate, ethyl acetate, and butyl acetate; ketone-based solvents such as methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone; and ether-based
• the alkaline solution may also contain a surfactant.
• the surfactant include various anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants, and among these, anionic surfactants and nonionic surfactants are preferred.
• anionic surfactants include alkylbenzenesulfonates, alkylphenylsulfonates, alkylnaphthalenesulfonates, higher fatty acid salts, sulfates of higher fatty acid esters, sulfonates of higher fatty acid esters, sulfates and sulfonates of higher alcohol ethers, higher alkyl sulfosuccinates, polyoxyethylene alkyl ether carboxylates, polyoxyethylene alkyl ether sulfates, alkyl phosphates, and polyoxyethylene alkyl ether phosphates.
• dodecylbenzenesulfonates include dodecylbenzenesulfonates, isopropylnaphthalenesulfonates, monobutylphenylphenol monosulfonates, monobutylbiphenylsulfonates, and dibutylphenylphenol disulfonates.
• nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters, glycerin fatty acid esters, polyoxyethylene glycerin fatty acid esters, polyglycerin fatty acid esters, sucrose fatty acid esters, polyoxyethylene alkylamines, polyoxyethylene fatty acid amides, fatty acid alkylol amides, alkyl alkanol amides, acetylene glycol, oxyethylene adducts of acetylene glycol, polyethylene glycol polypropylene glycol block copolymers, and the like.
• polyoxyethylene nonylphenyl ether polyoxyethylene octylphenyl ether, polyoxyethylene dodecylphenyl ether, polyoxyethylene alkyl ethers, polyoxyethylene fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, fatty acid alkylol amides, acetylene glycol, oxyethylene adducts of acetylene glycol, and polyethylene glycol polypropylene glycol block copolymers are preferred.
• surfactants that can be used include silicone surfactants such as polysiloxane oxyethylene adducts; fluorosurfactants such as perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, and oxyethylene perfluoroalkyl ethers; and biosurfactants such as spiculisporic acid, rhamnolipids, and lysolecithin.
• silicone surfactants such as polysiloxane oxyethylene adducts
• fluorosurfactants such as perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, and oxyethylene perfluoroalkyl ethers
• biosurfactants such as spiculisporic acid, rhamnolipids, and lysolecithin.
• surfactants can be used alone or in combination of two or more.
• the amount added is preferably in the range of 0.001 to 2 mass % of the total amount of the alkaline solution, more preferably 0.001 to 1.5 mass %, and even more preferably 0.01 to 1 mass %.
• the target laminate is immersed in the alkaline solution, which has been heated to 20 to 90°C, for example in a treatment tank.
• Heat or ultrasonic waves may be applied at this time.
• There are no particular limitations on the heating method and known heating methods using heat rays, infrared rays, microwaves, etc. may be used.
• Ultrasonic vibration may be applied, for example, by attaching an ultrasonic vibrator to the treatment tank and applying ultrasonic vibration to the alkaline solution.
• the alkaline solution is preferably stirred during immersion.
• stirring methods include mechanically stirring the dispersion of the laminate contained in the treatment tank with a stirring blade, water flow stirring with a water flow pump, and bubbling with an inert gas such as nitrogen gas. The above methods may be used in combination to efficiently peel off the multilayer film.
• the time for which the laminate is immersed in the alkaline solution depends on the structure of the laminate, but is generally in the range of 2 minutes to 48 hours. If the immersion time is less than 2 minutes, there is a risk that the adhesive layer will not completely peel off from the laminate and some of it will remain.
• the laminate may be immersed in the alkaline solution once or in several separate sessions.
• the laminate has an adhesive and a printed ink layer to display the product name and the like or to add decorativeness, but in the process of immersing in the alkaline solution, this printed ink layer can also be peeled off or dissolved.
• a metal foil or vapor deposition film such as aluminum is also laminated, but in the present invention, this metal foil or vapor deposition film can also be peeled off or dissolved.
• the alkaline solution used in the separation and recovery method acts on the interface between the laminate and the adhesive or printing ink, significantly reducing the adhesive strength, presumably causing interfacial peeling between the laminate and the adhesive or printing ink.
• cross-linked coatings of reactive adhesives and the like hardly dissolve in any solution, but in the present invention, they are not dissolved but rather cause interfacial peeling, so it is presumed that efficient separation and recovery can be performed in a short time.
• recycled plastics The laminate of the present invention can be separated into each substrate as described above, or the laminate or packaging of the present invention can be processed directly by various known recycling plastic processing methods to produce recycled plastic.
• recycled plastic can be obtained by a production method including a process of crushing the laminate of the present invention separated into each substrate, or the laminate or packaging of the present invention, a process of melting and kneading the crushed film pieces, and a process of pelletizing the melted and kneaded mixture.
• the crusher used for crushing is not particularly limited and any known crusher may be used.
• the crushed film pieces are physically blended by melt kneading, solvent cast blending, latex blending, polymer complex, etc.
• the melt kneading method is common.
• kneading devices include a tumbler, a Henschel mixer, a rotary mixer, a super mixer, a ribbon tumbler, a V blender, etc.
• the film pieces are melt kneaded by such a kneading device and then pelletized.
• a single-screw or multi-screw extruder is generally used for melt kneading pelletization, and the film pieces may be charged as they are or may be charged after being compressed and reduced in volume with or without heating.
• a Banbury mixer, a roller, a co-kneader, a blast mill, a Prabender blastograph, etc. can also be used, which are operated batchwise or continuously.
• the film pieces may be used as molding resins and melt kneaded in the heating cylinder of a molding machine without melt kneading.
• Polyester polyols (B3-2) to (B3-3) were obtained in the same manner as in Production Example 4, except that the raw materials used were changed as shown in Table 1.
• PK-400GD Sannix PK-400GD (manufactured by Sanyo Chemical Industries, Ltd., bifunctional polypropylene glycol, molecular weight 417)
• Gly glycerin T-403: Jeffamine T-403 (manufactured by Huntsman (USA), trifunctional polyether polyamine, molecular weight 440)
• EDP-300 Adeka Polyether EDP-300 (manufactured by Adeka Corporation, polypropylene glycol containing two tertiary amines in the molecule, molecular weight 300, OHV 750)
• EDP-450 Adeka Polyether EDP-450 (manufactured by Adeka Corporation, polypropylene glycol containing two tertiary amines in the molecule, molecular weight 450, OHV 500)
• polyisocyanate compound (E) 50 parts of a 20/30 (weight ratio) mixture of polypropylene glycol having a molecular weight of 1000/polypropylene glycol having a molecular weight of 2000 was gradually added in four portions, and the mixture was then heated to 80°C and reacted for a further 5 hours to obtain polyisocyanate compound (E).
• the NCO% of the obtained polyisocyanate compound (E) was 13.8%.
• polyester polyol (P) 200 parts of isophorone diisocyanate, and 60 parts of 2,2'-dimethylolpropionic acid were charged into a four-neck flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas inlet tube, and reacted at 75°C for 8 hours under a nitrogen stream to obtain a polyurethane resin (PU).
• PU polyurethane resin
• the aromatic ring concentration derived from the raw material monomer of the aromatic dicarboxylic acid was 2.8 mmol/g
• the ester bond group concentration was 6.6 mmol/g
• the acid value was 25 mg KOH/g.
• Ammonia was used as a neutralizing agent, and the mixture was neutralized so that the neutralizing agent/acid equivalent ratio was 1.05, and then diluted with water to obtain an aqueous dispersion of the polyurethane resin.
• composition for the primer layer was prepared by mixing 100 parts of the urethane resin (PU) with 3 parts of "Bayhydur Ultra BU3100” manufactured by Covestro, and then diluting the mixture with isopropyl alcohol (IPA) to a solid content of 10%.
• PU urethane resin
• IPA isopropyl alcohol
• the primer layer composition was printed on a stretched polypropylene (sometimes abbreviated as OPP) film that had been gravure-printed solidly with white printing ink (DIC's "Finart R794 White") using a gravure printing machine (manufactured by DIC Engineering Co., Ltd.) equipped with a gravure plate having a plate depth of 22 ⁇ m.
• OPP stretched polypropylene
• DINK4 White white printing ink
• Examples 1 to 6 and Comparative Examples 1 to 3 According to the formulations in Tables 4 and 5, the oil or fat (A) containing an acid anhydride group and the curing agent (H) were blended to prepare adhesive compositions, and various evaluations were performed.
• This configuration is abbreviated as OPP/CPP.
• (2) Manufacturing method of substrate 1/CPP laminate Using a laminator set to a lamination speed of 250 m/min, each prepared adhesive composition was applied to the substrate 1 so that the coating amount was about 1.8 g/ m2 solid content, and the substrate was laminated with a non-oriented polypropylene (sometimes abbreviated as CPP) film and cured at 40°C for 4 days to produce a laminate having substrate 1/white printing ink layer/adhesive layer/CPP film layer.
• CPP non-oriented polypropylene
• each prepared adhesive composition was applied onto a polyethylene terephthalate film so that the coating amount was about 1.8 g/m2 in solid content, and the film was cured at 40°C for 4 days to produce a film for evaluating biodegradability.
• Adhesive strength Adhesive strength
• Adhesive strength > 1.2N 3 Adhesive strength 0.8-1.2N (practical level) 2: Adhesive strength 0.5-0.8N 1: Adhesive strength ⁇ 0.5N
• Test pieces measuring 2 cm x 2 cm were cut out from the laminates of OPP/CPP structure for Examples 1 to 4, and from the laminates of Base material 1/CPP structure for Examples 5 and 6.
• the test pieces were immersed in 50 g of an alkaline solution of 2% sodium hydroxide at 70°C (the solvent for the alkaline solution is shown in the table) and stirred at 400 rpm, and the time required for each laminate to peel and whether or not the adhesive layer peeled off from the CPP film were measured.
• the adhesive was evaluated based on the ratio of adhesive remaining on the CPP film (residual rate).
• the residual rate of adhesive was calculated from the height of the absorption peak of the ester bond at 1740 cm-1 based on the IR measurement result of the film before the test, measured by FT-IR after the test. 5: Less than 5% (very good) 4: 5-20% (practical level) 3: 20-60% (not suitable for practical use) 2: 60-80% 1: >80%
• Compost decomposition was measured using the film for evaluating biodegradability according to a method in accordance with JIS K6953-1:2011. *Culture temperature: 58°C, culture period: 28 days *Evaluation criteria: 5: Compost decomposition rate is 50% or more 4: Compost decomposition rate is 40% or more and less than 50% 3: Compost decomposition rate is 25% or more and less than 40% 2: Compost decomposition rate is 15% or more and less than 25% (lower practical limit) 1: Compost decomposition rate is less than 15% (not suitable for practical use)
• Examples 1 to 6 not only had the necessary adhesive strength, but also had excellent releasability and biodegradability. On the other hand, the Comparative Example had poor releasability and biodegradability.

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